866 research outputs found
Novel Lifshitz point for chiral transition in the magnetic field
Based on the generalized Ginzburg-Landau theory, chiral phase transition is
discussed in the presence of magnetic field. Considering the chiral density
wave we show chiral anomaly gives rise to an inhomogeneous chiral phase for
nonzero quark-number chemical potential. Novel Lifshitz point appears on the
vanishing chemical potential line, which may be directly explored by the
lattice QCD simulation.Comment: 4pages,2figure
EP-1165 Technical advantages of dynamic tumor tracking in lung stereotactic body radiation therapy using a gimbaled linac
Satellite DNA in Paphiopedilum subgenus Parvisepalum as revealed by high-throughput sequencing and fluorescent in situ hybridization
Background: Satellite DNA is a rapidly diverging, largely repetitive DNA component of many eukaryotic genomes. Here we analyse the evolutionary dynamics of a satellite DNA repeat in the genomes of a group of Asian subtropical lady slipper orchids (Paphiopedilum subgenus Parvisepalum and representative species in the other subgenera/sections across the genus). A new satellite repeat in Paphiopedilum subgenus Parvisepalum, SatA, was identified and characterized using the RepeatExplorer pipeline in HiSeq Illumina reads from P. armeniacum (2n = 26). Reconstructed monomers were used to design a satellite-specific fluorescent in situ hybridization (FISH) probe. The data were also analysed within a phylogenetic framework built using the internal transcribed spacer (ITS) sequences of 45S nuclear ribosomal DNA.
Results: SatA comprises c. 14.5% of the P. armeniacum genome and is specific to subgenus Parvisepalum. It is composed of four primary monomers that range from 230 to 359 bp and contains multiple inverted repeat regions with hairpin loop motifs. A new karyotype of P. vietnamense (2n = 28) is presented and shows that the chromosome number in subgenus Parvisepalum is not conserved at 2n = 26, as previously reported. The physical locations of SatA sequences were visualised on the chromosomes of all seven Paphiopedilum species of subgenus Parvisepalum (2n = 26–28), together with the 5S and 45S rDNA loci using FISH. The SatA repeats were predominantly localisedin the centromeric, peri-centromeric and sub-telocentric chromosome regions, but the exact distribution pattern was species-specific.
Conclusions: We conclude that the newly discovered, highly abundant and rapidly evolving satellite sequence SatA is specific to Paphiopedilum subgenus Parvisepalum. SatA and rDNA chromosomal distributions are characteristic of species, and comparisons between species reveal that the distribution patterns generate a strong phylogenetic signal. We also conclude that the ancestral chromosome number of subgenus Parvisepalum and indeed of all Paphiopedilum could be either 2n = 26 or 28, if P. vietnamense is sister to all species in the subgenus as suggested by the ITS data
L-Tryptophan Production by Auxotrophic and Analogue Resistant Mutants of Aureobacterium flavescens
A number of tyrosine plus phenylalanine double auxotrophic mutants were isolated by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) treatment of a locally isolated strain of Aureobacterium flavescens of which 11A39 and 11A17 were selected on the basis of their tryptophan production in a mineral salt medium over other isolated mutant strains. The mutational block in the aromatic amino acid biosynthetic pathway of the selected double auxotrophs were determined. By controlling pH of the production medium to near neutrality, the active growth period could be extended up to 72 h and more tryptophan was accumulated compared to pH unregulated culture where the active growth ceased after 48 h. Further improvement of the tryptophan production has been achieved by stepwise isolation of a mutant strain resistant to the tryptophan analogues p-fluorotryptophan (FT) and 5-methyl tryptophan (MT) from the 11A39. Demand for L-tryptophan as food additive and therapeutic agent is increasing day by day throughout the World, particularly in the underdeveloped and developing countries like India. Still to date India depends on other countries for L-tryptophan. The aim of this work is to develop a potent high yielding, feed back insensitive mutant strain and optimization of its medium pH for maximum production of tryptophan
Orthorhombic Phase of Crystalline Polyethylene: A Constant Pressure Path Integral Monte Carlo Study
In this paper we present a Path Integral Monte Carlo (PIMC) simulation of the
orthorhombic phase of crystalline polyethylene, using an explicit atom force
field with unconstrained bond lengths and angles. This work represents a
quantum extension of our recent classical simulation (J. Chem. Phys. 106, 8918
(1997)). It is aimed both at exploring the applicability of the PIMC method on
such polymer crystal systems, as well as on a detailed assessment of the
importance of quantum effects on different quantities. We used the
ensemble and simulated the system at zero pressure in the temperature range 25
- 300 K, using Trotter numbers between 12 and 144. In order to investigate
finite-size effects, we used chains of two different lengths, C_12 and C_24,
corresponding to the total number of atoms in the super-cell being 432 and 864,
respectively. We show here the results for structural parameters, like the
orthorhombic lattice constants a,b,c, and also fluctuations of internal
parameters of the chains, such as bond lengths and bond and torsional angles.
We have also determined the internal energy and diagonal elastic constants
c_11, c_22 and c_33. We discuss the temperature dependence of the measured
quantities and compare to that obtained from the classical simulation. For some
quantities, we discuss the way they are related to the torsional angle
fluctuation. In case of the lattice parameters we compare our results to those
obtained from other theoretical approaches as well as to some available
experimental data. In order to study isotope effects, we simulated also a
deuterated polyethylene crystal at a low temperature. We also suggest possible
ways of extending this study and present some general considerations concerning
modeling of polymer crystals.Comment: 18 pages, RevTex, 18 figures, 3 tables, submitted to Phys. Rev.
3D FCN Feature Driven Regression Forest-Based Pancreas Localization and Segmentation
This paper presents a fully automated atlas-based pancreas segmentation
method from CT volumes utilizing 3D fully convolutional network (FCN)
feature-based pancreas localization. Segmentation of the pancreas is difficult
because it has larger inter-patient spatial variations than other organs.
Previous pancreas segmentation methods failed to deal with such variations. We
propose a fully automated pancreas segmentation method that contains novel
localization and segmentation. Since the pancreas neighbors many other organs,
its position and size are strongly related to the positions of the surrounding
organs. We estimate the position and the size of the pancreas (localized) from
global features by regression forests. As global features, we use intensity
differences and 3D FCN deep learned features, which include automatically
extracted essential features for segmentation. We chose 3D FCN features from a
trained 3D U-Net, which is trained to perform multi-organ segmentation. The
global features include both the pancreas and surrounding organ information.
After localization, a patient-specific probabilistic atlas-based pancreas
segmentation is performed. In evaluation results with 146 CT volumes, we
achieved 60.6% of the Jaccard index and 73.9% of the Dice overlap.Comment: Presented in MICCAI 2017 workshop, DLMIA 2017 (Deep Learning in
Medical Image Analysis and Multimodal Learning for Clinical Decision Support
Emergence of Clostridium botulinum type B-like nontoxigenic organisms in a patient with type B infant botulism
金沢大学大学院医学系研究科病態検査学We encountered a patient with infant botulism caused by a single clone of Clostridium botulinum type B. In the early convalescent phase, a C. botulinum type B-like nontoxigenic organism emerged in the feces instead. Growth inhibition of toxigenic strains by nontoxigenic strains was examined
The effect of matured date palm tree ( Phoenix dactylifera
The effect of a hot water extract of matured date palm tree fruit on allergic responses was investigated in NC/Nga mice. The allergic score was significantly reduced in the mice fed a date palm tree fruit extract-added diet than the fruit extract-free diet. The levels of serum antigen-specific immunoglobulin E and spleen interleukin (IL)-4+CD4+ cells were significantly lowered in the mice fed the fruit extract-added diet. Bruton's tyrosine kinase (Btk) and IL-2-inducible T cell kinase (Itk) mRNA expressions in spleen cells were significantly lowered in the mice fed the fruit extract-added diet. Moreover, chlorogenic acid and pelargonin decreased these mRNA expressions in C3H/HeN mouse spleen cell cultures. These results suggest that the date palm tree fruit extract may reduce allergic symptoms in mice via a decrease in the number of type 2 helper T (Th2) cells, and a suppression of the expression of kinases involved in mast cell degranulation and Th2 cell differentiation.ArticleFOOD AND AGRICULTURAL IMMUNOLOGY. 25(1):49-60 (2014)journal articl
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